Safety belts are normally protracted by a user to a position beyond that required for use, buckled to an element that is affixed to the structure of the vehicle, and thereafter allowed to retract against the body of the user. The belt is automatically locked against further protraction thereby to secure the user in the seat in the event of sudden vehicle deceleration.
Since retraction of the safety belt is spring biased, pressure on the body of the user is sometimes uncomfortable. To alleviate this problem, comfort mechanisms have been devised to restrain the retraction force on the belt. Such comfort mechanisms require a slight protraction after retraction of the belt to effect lockup. Release of the comfort mechanism requires yet another protraction, which, when the belt is substantially fully extended, may be impossible without disconnecting the belt from its anchor, or opening the vehicle door.
The comfort mechanism comprises a plastic disc which is attached to the spool of the retractor and which is provided with a track on an external face adapted to receive a spring wire follower which rides therein.
As taught in our U.S. Pat. No. 4,002,311, the contents of which are incorporated herein by reference, the comfort mechanism disc has a first track portion within which the end of the spring follower travels during initial protraction of the belt.
A second track portion is disposed radially outwardly of the first track and communicates therewith to perform a double function; first, to receive the follower when the belt is initially retracted following the initial protraction, and, second, to permit continuous retraction of the belt when the belt is unlatched by the user and the belt is returned to the housing.
A third or control portion of the track is in open communication with the second track and forms a continuation thereof in the direction of protraction relative to the follower. The follower is engageable with a stop in the third track upon a subsequent but limited protraction of the belt initiated by the user to relieve tension
Disengagement of the follower and the stop is achieved either by protraction of the belt by the user or by a mechanical or electromechanical release operating in response to the user's unlatching of the belt. Because a certain amount of protraction of the belt is sometimes necessary to disengage the stop, disengagement may be rendered impossible when the belt is substantially entirely protracted from the retractor.